Metallurgical apparatus.



PATENTED SEPT. 8,71908'. W. A. MERRALLS.

METALLURGIUAL APPARMUS. APPLIATION FILED DBO. 18, 1906. RENBWED JULY 29,1908.

W-ILLIAM A. MERRALLS, OF SAN FRANCISCO, CALIFORNIA.

METALLURGICAL APPARATUS.

Specification of Letters Patent.

Patented Sept. 8, 1908.

Application filed December 18, 1906, Serial No. 348,492. Renewed July29, 1908. Serial No. 445,928.

To all whom it may concern):

Be it known that l, WILLIAM A. MER- RALLs, a citizen of the UnitedStates, residing at San Francisco, in the county of San Francisco andState of California, have invented new and useful Improvements inMetallurgical Apparatus, of which the following is a specification.

The object of this invention is to provide an improved apparatus formetallurgical pur.- poses, and particularly for the treatment of oreswith cyanid solutions. the apparatus the cyaniding can be effected moreexpeditiously than heretofore and with greater economy, both in originalcost and in operating expense. l

In the accompanying drawing, the figure is a vertical section of' a'preferred form of apparatus embodying the invention.- t Referring tothe drawing, 1 indicates a tank, in which the several steps of theprocess are performed. Said tank is made sufficiently strong towithstand considerable intei-nal pressure, and for this pur ose the top2 of the tankis secured to the ottom 3 by means of suitably arrangedstay-bolts 4.

The wall of the tank is also encompassed with strong bands 5.

The material to be treated is admitted through an inlet 6 in the top ofthc tank, and may flow out at the top by an outlet 7 therein.

8 is a discharge opening in the wall through which the refuse can bedischarged. The material to be treated 'ma be the tailings from a stampor othermill, the liquid portion being only the Water used in theoperation ofpulverizing the material in the mill or the ore may bepulverized dry and introduced into'the tank, and water may be added; orlime solution may be added for sweetening an acid ore; or cyanidsolution may beladded; or it may be the material alread treated with thecyanid solution in the mil when pulverizing. In the first cases, whenplain water or lime solution only is used, a sufficient quantity of thewater and pulp is first allowed to pass into the tank by the inlet 6 andout by theoutlet 7 until the pul is sufficiently concentrated thereinfor a ciarge, andthe openings 6, 7, are then closed. The water must nowbe expelled from the tank. Y

The solid material will naturally tend to settle with a surface slo ingdownwards from the inlet opening, and should now be'stirred.

By the use of For this purpose, an agitator is used, preferably in theform of a propeller 9 on a vertical the hub of said bevel gear having acircular p late or flange 21, which, on the'side o posite to the bevelpinion 15 is held down y a roller 22. By this construction the ropeller9 1s given a rotary motion within tilde tank, stirring up the pul anddistributing it uniformly therethrough The material in the tank is nowin the proper condition for the expulsion of the water. The bottom ofthe tank is formed with a filter of any form commonly used in cyaniding,the form here shown consisting of cloth 23 interposed between upper andlower wooden screens 24, resting upon beams 49 having' grooves 50 in thelower edge. Some of the water will have already escaped through saidfilter. To force the water through the filter,` compressedair' is nowadmitted in the top of the tank by a pipe 25. The expulsive action ofthe air is greatly assisted by the agitation of the pulp by the rotatingpropeller, and the propeller is caused to descend in the tank Vwith thelevel of the waterthercin so as to continue the agitation of the layerof sand and the slimes left by the expelled water. To provide for thisdescent of the propeller, the top of the shaft 10 has secured thereto adisk 26 on which rests a plate 27 of phosphor bronze on whichis a plate28 of steel, upon which rests another plate 29 of phosphor bronze, uponwhich rests a disk 3() secured to a piston rod 31, around which is acollar 32 of iron with a lower faein of phosphor bronze. The lower disk26 an the upper collar 32 are secured together by means of a suitablenumber of U-clamps 33, With this construction, the propeller shaft 1'0can rotate freely, and at the saine time move vertically with the pistonrod, which itself does not rotate. Said rod 31 is secured to a piston34, which reciprocates in a cylinder 85 supported by posts 36. Saidpiston may be operated in either direction by any pressure fluid passedthrough pipes 37 controlled by a four way valve 48. In order to preventthe piston 34 rotating,

its rod is continued upwards into a tubular guide 38 secured upon thetop of the cylinder, said rod havinghgrooves 89 engaged by feathers 40.The p osphor bronze plates are for the purpose ofpermitting thepropeller shaft to. rotate without undue friction, notwithstanding thatthe piston rod itself does not rotate.

By the admission of the pressure fluid into the cylinder 35, thepropeller can be raised or lowered while in rotation,y and consequentlycan be applied to the pulp, as the -water descends, to disperse the`same and permit the permeation of the liquidy therethrough to allow litto escape through the filtering material. The propeller, rotating atalhigh speed, in one direction produces a owerful suction towards thecenter at the ottom of the tank, creating a very rapid vortex motion ofthe Water, which thus very qllliickly takes up in suspension the wholeof t e solid matter in the tank. If rotated in the opposite'direction,the suction is at the top of the tank and the water and solid matter aredrivenvoutwards at the bottom, but the same vortex effect is produced.,By this ymeans the slimes and other solid material are prevented fromunduly packing, While the compressed air powerfully depresses the waterand forces it out through the iilterlng material, the water passinthrough an outsteps would not be necessary. The water,

or lime solution, as the case may be, having been expelled from the tankand only the solid material containing the values now remaining therein,the cyanid solution is admitted to the tank through a ipe 41, whereuponthe tank having been led, or nearly filled with the solution, and thepipe 41 havin been closed, the first ste is to effect the 1 so ution ofthe gold. For t 's purpose the propeller is set in motion, and thismotion is continued until the whole of the contents of the tank are inthorough agitation, and uniformly dispersed throu hout the interior ofthe tank, and fora sucient length of time to permit the cyanid solutionto thoroughly act u on and dissolve the gold.

W en the gold has been completely dissolved, it is then necessary toexpel the solution from the tank. For this purpose comressed air is aain admitted into t e tank in fiks manner as efore, and the pressure ofthe air on the top of the solution forces the soluessere tion throughthe filtering material, and out through the pipe 45. By maintaining thepropeller in operation simultaneously with the admission of compressedair the slimes are not allowed to settle, and thus clog up the filteringmaterial, and the expulsion of the solution through the filteringmaterial is thus rendered comparatively easy. The solution thus expelledis conducted to the zinc boxes or other like devices and treated in theordinary manner as now practiced in cyaniding to recover the goldtherefrom;

When all of the solution has been expelled and thoroughly washed, waterbeing added for that purpose, either by gravity or under pressure, theresidual cake of solid material must be removed from the tank, which maybe done either by hand, or by hydraulicing it out with water.l Or asufficient quantity of water may be turned into the tank, the propellerstarted, and the solid material thereby dispersed and suspended in thewater in the same manner as it was in the cyanid solution, and may berun out of the tank through the outlet 8.'

42 indicates sight-holes through which the interior of the tank may beinspected, the

inner surfaces of the glass windows therein` being washed by water froma conduit 43. Electric lamps 44 are also provided to illuminate theinterior of 'the tank. A pressure gage 46 indicates the pressure in thetank.

While only the specific metal, gold, is referred to in thespecification, this is for the sake of brevity and clearness only,l andit is to be understood that the apparatus herein disclosed 'and claimedcan be used, for the recovery of all metals for which cyaniding is, orcan, be practiced.

. I claim 1. Metallurgical apparatus comprising a closed tank, a filterin the lower ortion thereof, a liquid outlet beneath said ter, amechanical agitator in said tank, sources of supply for pulp, solutionsand compressed air, connections bet veen said sources of supply and theupper portion of said tank, and means for closing said connections.

2. Metallurgical apparatus comprisin` a closed tank, a filter in thelower portion thereof, protecting means for the upper surface of saidfilter, a liquid outlet beneath said filter, a mechanical agitator insaid tank,

sources of supply for pulp, solutions and' compressed alr, connectionsbetween said sources of sup ly and the upper portion of said tank, anmeans for closing said connections. v.

3. Metallurgical apparatus comprising a closed tank, a filter in thelower portion thereof, a liquid outlet beneath said filter, a rotatableagitator vertically adjustable in said tank, sources of supply for pulp,solutions and compressed air, connections between said sources of supplyand the upper portion of said` tank, and' means for closing sai'dconnections.

4. Metallurgical apparatus comprising a closed tank, a filter in4 thelower portion thereof, protecting means for theupper surface of saidfilter, a liquid outlet beneath said `ilter, a mechanical agitator insaid' tank, sources of 'supply forA pulp, solutions and compressed air,connections between said sources of supply and the upper portions ofsald tank, means for closing sald connectlons,

myhand in the presence of two subscribing wltncsses.

WILLIAM AMERRALLS.

Witnesses f FRANCIS M. WRIGHT, D. B. RrcHARDs.

